Wy. Liu et Gx. Zhu, A NEW METHOD OF SIMULATING FOCUSING GRADIENT-BASED ON FAST STRATIFIEDFILTERING ON 3D IMAGE, Hongwai yu haomibo xuebao, 17(5), 1998, pp. 357-362
The relationship between fuzzy function a and the distance from object
to lens and focal Length was provided by using the lens model. A new
adaptive stratified filtering method for 3-D depth image was developed
. The concept of the difference function was proposed and the depth im
age was resolved into several non-intersection sub-level images along
z axis. The algorithm complexity was reduced and the postfiltration er
ror was controlled within a given range by filtering and composing sub
-level images. The problems of boundary and obstruction were solved by
introducing alpha value and composing subimages level by level. This
method has been successfully used in computer graphics rendering algor
ithm and an example of simulating defocus of camera was given.